Is the time right for quantitative public health guidelines on sitting? A narrative review of sedentary behaviour research paradigms and findings

Embodied navigation: the influence of lived experience on physical activity and sedentary behavior among older adults

PURPOSE

The impact of a sedentary lifestyle on health and well-being is well recognized. However, there is limited understanding of how a lifetime of physical activity and sedentary behaviour influences an active lifestyle in older adults. The aim of this study was to describe how lived experience of physical activity and sedentary behaviour impacts daily activities among older adults, from a life course perspective.

METHODS

Qualitative content analysis was used; individual telephone interviews were conducted with fourteen older adults aged 71 to 92 years. The participants received initial support from community care and lived in ordinary housing in southern Sweden.

RESULTS

The interviews yielded one theme, "Navigating with an embodied activity compass," and two sub-themes: "Being guided by the past" and "Unveiling pathways through body awareness."

CONCLUSIONS

Our study highlights how older adults' lived experiences of physical activity, with their connections to body awareness and acceptance, impact daily physical activity. These findings offer new knowledge for clinical practitioners balancing recommendations of sedentary behaviour and physical activity, to promote healthy daily physical activity among older adults. Future research and policies should consider the lived experiences of older adults when addressing public health matters related to sedentary behaviour and physical activity.

Extending Our Understanding of the Social Determinants of Physical Activity and Sedentary Behaviors in Families: A Systems Mapping Approach

BACKGROUND

The social environment is important to consider for effective promotion of movement behaviors like increased physical activity (PA) and reduced sedentary behavior (SB); yet, it is less often considered than individual and built environments. One way to advance social environment research is to develop system maps, an innovative, participatory, action-oriented research process that actively engages stakeholders to visualize system structures and explore how systems "work." The purpose of this research was to develop PA and SB system maps of the social environment embedded within the core/nuclear family system.

METHODS

The development process began with a 2-day multicountry, 16-researcher, in-person participatory workshop in August 2023, followed by multiple online follow-up consultations. Attendees contributed to the creation of the maps through shared development of critical determinants and their causal pathways. The structure of the final maps was analyzed using network analysis methods to identify indicators of centrality, and key feedback loops and areas for potential intervention were explored.

RESULTS

Key central determinants that were likely critical targets for systems intervention to produce changes in PA and SB and featured prominently in most of the reinforcing and balancing feedback loops included shared family interests, values and priorities, family logistical support, family cohesion/organization, and shared experiences. The maps also highlighted key determinants of the broader social environment external to the family.

CONCLUSIONS

These system maps support current evidence on movement behaviors in family systems and socioecological theories and have the utility to galvanize future research and policy to promote PA and reduce SB.

Accelerometer-Measured Sedentary Behavior and Risk of Future Cardiovascular Disease

BACKGROUND

Beyond serving as a marker for insufficient physical activity, sedentary behavior may directly affect future cardiovascular (CV) disease risk.

OBJECTIVES

This study sought to examine associations between accelerometer-measured sedentary behavior with risk of specific CV outcomes, including potential relations with moderate to vigorous physical activity (MVPA).

METHODS

Among participants of the UK Biobank prospective cohort study, we fit Cox models adjusted for demographic and lifestyle factors to assess associations between accelerometer-measured daily sedentary time with incident atrial fibrillation (AF), myocardial infarction (MI), heart failure (HF), and CV mortality. We assessed the potential effect of MVPA on associations between sedentary time and CV disease by including MVPA as an adjustment variable, as well as performing subgroup analyses stratified at the guideline-recommended MVPA threshold (ie, ≥150 min/wk). We then performed compositional analyses to estimate the effects of reallocating sedentary time to other activities.

RESULTS

Among 89,530 individuals (age 62 ± 8 years, 56.4% women) undergoing 1 week of accelerometry, median sedentary time was 9.4 h/d (Q1-Q3: 8.2-10.6). In multivariable models, using the second quartile (8.2-9.4 h/d) as a referent, sedentary time in the top quartile (>10.6 h/d) was associated with greater risks of HF (HR: 1.45; 95% CI: 1.28-1.65) and CV mortality (HR: 1.62; 95% CI: 1.34-1.96), with an inflection of risk at 10.6 h/d. Higher sedentary time was also associated with greater risks of incident AF (HR: 1.11; 95% CI: 1.01-1.21) and MI (HR: 1.15; 95% CI: 1.00-1.32), with an approximately linear relation. Associations with HF and CV mortality persisted among individuals meeting guideline-recommended MVPA levels. Among individuals with >10.6 h/d of sedentary time, reallocating sedentary behavior to other activities substantially reduced the excess CV risk conferred by sedentary behavior (eg, 30-minute decrease in sedentary time for HF: HR: 0.93; 95% CI: 0.90-0.96), even among individuals meeting guideline-recommended MVPA (HR: 0.93; 95% CI: 0.87-0.99).

CONCLUSIONS

Sedentary behavior is broadly associated with future adverse CV outcomes, with particularly prominent effects on HF and CV mortality, where risk inflected at approximately 10.6 h/d. Although guideline-adherent MVPA partially mitigates excess risk, optimizing sedentary behavior appears to be important even among physically active individuals.

Does sedentary time and physical activity predict chronic back pain and morphological brain changes? A UK biobank cohort study in 33,402 participants

BACKGROUND

The relationship between sedentary time, physical activity, and chronic back pain remains unclear. The study aims to investigate whether sedentary time and physical activity predict chronic back pain and morphological brain changes.

METHODS

This cohort study recruited adults aged 37-73 years enrolled between 2006 and 2010, with follow-up until 2014. The total cohort comprised 33,402 participants (mean age: 54.53). Data were collected on daily sedentary time, physical activity, lifestyle factors, and health outcomes.

RESULTS

After nearly 8-year follow-up, 3,006 individuals (9.00%) reported chronic back pain in total. Individuals with daily sedentary time exceeding 6 h had a 33% higher risk of chronic back pain compared to those with sedentary time of 2 h or less (RR, 1.33, 95%CI, 1.17-1.52). Sedentary time was also associated with decreased grey matter volume in several brain regions, including bilateral primary somatosensory cortex (S1), secondary somatosensory cortex, putamen, primary motor cortex (M1), insula, hippocampus, amygdala, as well as right supplementary motor area, left medial frontal cortex, and right anterior cingulate cortex (FDR-corrected p-value < 0.05). Compared to individuals who sat for more than 6 h with light physical activity, those engaging in moderate physical activity with sedentary time of 2 h or less (RR, 0.71, 95%CI, 0.52-0.99) exhibited a significant decrease in chronic back pain risk. In addition, replacing sedentary time with equivalent amount of physical activity also demonstrated a reduction in the risk of chronic back pain (RR, 0.87, 95%CI, 0.77-0.99) and increased the reginal grey matter volumes including the amygdala, insula, M1, putamen and S1.

CONCLUSIONS

Prolonged sedentary time is associated with heightened risks of chronic back pain and deterioration in brain health.

Independent, Stratified, and Joint Associations of Sedentary Time and Physical Activity With Cardiovascular Disease: A Systematic Review

BACKGROUND

Recent statistics highlight cardiovascular diseases (CVD) as a major global cause of death. This review examines the methodological approaches and the main results of independent, stratified, and joint association of sedentary time (ST) and physical activity (PA) on CVD outcomes.

METHODS

We searched PubMed, Embase, Web of Science, and Scopus for prospective cohorts that examined the independent, stratified, or joint associations of ST and PA with CVD outcomes. Independent associations were defined as analyses mutually adjusted for PA and ST. Stratified associations were considered when there was a reference group in each stratum of PA or ST, and joint associations were defined by a single reference group for all other combined categories of ST and PA levels.

RESULTS

Of 45 articles, 69% explored independent association of ST or PA on CVD outcomes, while 31% using a stratified/joint approach. Most studies used self-reports for ST and PA and focused on CVD mortality. Mutually adjusted analyses identified ST positively and PA inversely associated to CVD outcomes. Stratified studies showed higher ST's pronounced impact on CVD for lower PA levels. High PA mitigated but did not eliminate ST's negative impact. Joint analyses revealed highest CVD risk in those with both high ST and low PA, and elevated risk in various intermediate combinations.

CONCLUSIONS

Employing independent, stratified, and joint association approaches can yield distinct and complementary public health messages aimed at promoting cardiovascular health. Recommendations should aim to not only to encourage boosting PA levels, but also, concurrently decrease ST.

Association of physical activity and sitting time with tobacco and alcohol use in 222,495 adolescents from 66 countries

BACKGROUND

The prevalence of tobacco and alcohol use among adolescents is alarming, and these substances are among the leading risk factors for current and future health among adolescents. Physical activity has the potential to help prevent substance use among adolescents. The objective of this study was to evaluate the association between physical activity, modes of transportation to or from school, and sitting time with tobacco and alcohol use among 222,495 adolescents.

METHODS

This cross-sectional study used data from national surveys conducted in 66 countries, obtained through the Global School-based Student Health Survey, and included adolescents aged 11 to 17 years. Information on physical activity, transportation to or from school, sitting time, and tobacco and alcohol use was collected through self-report questionnaires. Generalized linear models were employed to estimate the associations between these variables.

RESULTS

The analysis, adjusted for sex, age, and region, revealed that being physically active was associated with lower odds of smoking (OR: 0.86, 95%CI: 0.83-0.89), alcohol use (OR: 0.74, 95%CI: 0.72-0.76), binge drinking (OR: 0.66, 95%CI: 0.62-0.69), and drunkenness (OR: 0.85, 95%CI: 0.83-0.88) compared to inactivity. Insufficiently active participants also had lower odds of tobacco use (OR: 0.83, 95%CI: 0.80-0.85), alcohol use (OR: 0.77, 95%CI: 0.75-0.79), binge drinking (OR: 0.91, 95%CI: 0.87-0.96), and drunkenness (OR: 0.88, 95%CI: 0.85-0.90) compared to inactive participants. Additionally, active transportation to or from school was associated with lower odds of tobacco use (OR: 0.97, 95%CI: 0.95-0.99), alcohol use (OR: 0.94, 95%CI: 0.92-0.96), and binge drinking (OR: 0.78, 95%CI: 0.75-0.81) compared to those using passive transportation. Participants with acceptable sitting time, however, were more likely to use tobacco (OR: 1.48, 95%CI: 1.45-1.52), use alcohol (OR: 1.68, 95%CI: 1.64-1.72), binge drink (OR: 1.68, 95%CI: 1.62-1.75), and experience drunkenness (OR: 1.66, 95%CI: 1.62-1.69) compared to those with excessive sitting time.

CONCLUSION

Being physically active, even at insufficient levels, may have beneficial effects on tobacco and alcohol use in adolescents. Acceptable sedentary time, on the other hand, was positively associated with tobacco and alcohol use.

Reflections on four decades of physical activity epidemiology

•Broad topics in physical activity (PA) epidemiology have remained the same over 40 years; specific issues and questions have changed and challenges remain. •Accelerometry has made many advances in PA measurement, but created new methodological challenges. •The benefit of regular PA for a wide array of health outcomes has been well-established, but specificity is still needed about dose response relations. •Interventions in the population have led to increased prevalence of recommended levels of PA, but prevalence is still less than optimal and there are racial and ethnic disparities.

Associations between Recreational Screen Time and Brain Health in Middle-Aged and Older Adults: A Large Prospective Cohort Study

OBJECTIVES

To investigate the associations of recreational screen time with risks of brain-related disorders (dementia, stroke, and Parkinson's disease) and neuroimaging features.

DESIGN

Prospective cohort study.

SETTING AND PARTICIPANTS

A total of 407,792 participants from the UK Biobank who were free of dementia, stroke, or Parkinson's disease at enrollment (2006-2010).

METHODS

TV viewing and time spent using the computer were self-reported at baseline. Among a subsample of 40,692 participants, neuroimaging features were measured by magnetic resonance imaging in 2014. Data were analyzed using Cox proportional hazard models, restricted cubic spline models, and general linear regression models.

RESULTS

During a median follow-up of 12.6 years, 5227 incident dementia, 6822 stroke, and 2308 Parkinson's disease cases were identified. Compared with TV viewing >0-1 h/day, watching TV ≥5 h/day was associated with higher risks of dementia [hazard ratio (HR), 1.44; 95% confidence interval (CI), 1.28-1.62], stroke (HR, 1.12; 95% CI, 1.01-1.25), and Parkinson's disease (HR, 1.28; 95% CI, 1.06-1.54). Moreover, we observed inverse associations between TV viewing time and both gray matter volume and hippocampus volume (Ptrend <.001). However, we did not observe the significant associations between discretional computer use and brain-related disorders or neuroimaging features.

CONCLUSIONS AND IMPLICATIONS

Our findings suggest that high TV viewing time is associated with increased risk of various brain-related disorders, highlighting recreational TV viewing could have an important impact on brain-related health.

Health, Performance Ratings and Approachability of 50-60-Year-Old Sedentary Adults (ActIv-Study): Key Insights for Health Economy and Exercise Promotion

Despite significant prevention efforts, the numbers of physically inactive individuals, chronic illnesses, exhaustion syndromes and sick leaves are increasing. A still unresolved problem with exercise promotion is the low participation of sedentary persons. This collective term covers heterogeneous subgroups. Their engagement with movement campaigns and resistance to change are influenced by numerous factors. Our aim was to analyse survey data on health, performance, lifestyle habits and the approachability to physical activity campaigns obtained from the Germany-wide ActIv survey. From 2888 study participants aged 50-60 years, 668 persons were categorised into the subgroups "never-athletes", "sports-dropouts", "always-athletes" and "sports-beginners". Large and significant group differences were found for BMI, assessment of quality of life, health and fitness, risk factors and health problems. In total, 42.5% of "never-athletes" and 32.5% of "sports-dropouts" did not state any barriers to sport. There are substantial disparities between the non-athlete groups in terms of their motivation to exercise. In contrast, there are comparatively minor differences in motivation between "sports-dropouts" and "sports-beginners", whose health and fitness are the primary motivators for sport. Our analyses suggest that (i) negative health and performance trends cannot be compensated for by appeals for voluntary participation in exercise programmes and (ii) powerful incentive systems are required.

A systematic umbrella review and meta-meta-analysis of eHealth and mHealth interventions for improving lifestyle behaviours

The aim of this meta-meta-analysis was to systematically review randomised controlled trial (RCT) evidence examining the effectiveness of e- and m-Health interventions designed to improve physical activity, sedentary behaviour, healthy eating and sleep. Nine electronic databases were searched for eligible studies published from inception to 1 June 2023. Systematic reviews with meta-analyses of RCTs that evaluate e- and m-Health interventions designed to improve physical activity, sedentary behaviour, sleep and healthy eating in any adult population were included. Forty-seven meta-analyses were included, comprising of 507 RCTs and 206,873 participants. Interventions involved mobile apps, web-based and SMS interventions, with 14 focused on physical activity, 3 for diet, 4 for sleep and 26 evaluating multiple behaviours. Meta-meta-analyses showed that e- and m-Health interventions resulted in improvements in steps/day (mean difference, MD = 1329 [95% CI = 593.9, 2065.7] steps/day), moderate-to-vigorous physical activity (MD = 55.1 [95% CI = 13.8, 96.4] min/week), total physical activity (MD = 44.8 [95% CI = 21.6, 67.9] min/week), sedentary behaviour (MD = -426.3 [95% CI = -850.2, -2.3] min/week), fruit and vegetable consumption (MD = 0.57 [95% CI = 0.11, 1.02] servings/day), energy intake (MD = -102.9 kcals/day), saturated fat consumption (MD = -5.5 grams/day), and bodyweight (MD = -1.89 [95% CI = -2.42, -1.36] kg). Analyses based on standardised mean differences (SMD) showed improvements in sleep quality (SMD = 0.56, 95% CI = 0.40, 0.72) and insomnia severity (SMD = -0.90, 95% CI = -1.14, -0.65). Most subgroup analyses were not significant, suggesting that a variety of e- and m-Health interventions are effective across diverse age and health populations. These interventions offer scalable and accessible approaches to help individuals adopt and sustain healthier behaviours, with implications for broader public health and healthcare challenges.

Association of 'Tortoise' and 'Hare' movement behavior patterns with cardiometabolic health, body composition, and functional fitness in older adults

We investigated the association of movement behavior patterns with cardiometabolic health, body composition, and functional fitness in older adults. A total of 242 older adults participated of this cross-sectional study. Sedentary time, light physical activity (LPA) and moderate-vigorous physical activity (MVPA), steps/day, and step cadence were assessed by accelerometry. The movement behavior patterns were derived by principal component analysis. Cardiometabolic health was defined by a metabolic syndrome score (cMetS). Body composition was determined by appendicular lean mass/body mass index (ALM/BMI). Functional fitness was assessed by a composite z-score from the Senior Fitness Test battery. Two patterns were identified: 'Tortoise' (low sedentary time, high LPA and steps/day) and 'Hare' (high MVPA, steps/day, and step cadence). 'Tortoise' and 'Hare' were associated with better cMetS. 'Hare' was positively associated with ALM/BMI and Functional Fitness. While 'Tortoise' and 'Hare' were associated with better cMetS, only 'Hare' was associated with better ALM/BMI and functional fitness.

Effectiveness of workplace interventions with digital elements to reduce sedentary behaviours in office employees: a systematic review and meta-analysis

BACKGROUND

Digital interventions are potential tools for reducing and limiting occupational sedentary behaviour (SB) in sedentary desk-based jobs. Given the harmful effects of sitting too much and sitting for too long while working, the aim of this systematic review and meta-analysis was to examine the effectiveness of workplace interventions, that incorporated digital elements, to reduce the time spent in SB in office workers.

METHODS

Randomised control trials that evaluated the implementation of workplace interventions that incorporated digital elements for breaking and limiting SB among desk-based jobs were identified by literature searches in six electronic databases (PubMed, Web of Science, Scopus, CINAHL, PsycINFO and PEDro) published up to 2023. Studies were included if total and/or occupational SB were assessed. Only studies that reported pre- and postintervention mean differences and standard deviations or standard errors for both intervention arms were used for the meta-analysis. The meta-analysis was conducted using Review Manager 5 (RevMan 5; Cochrane Collaboration, Oxford, UK). Risk of bias was assessed using the Standard Quality Assessment Criteria for Evaluating Primary Research Papers from a Variety of Fields QUALSYST tool.

RESULTS

Nineteen studies were included in the systematic review. The most employed digital elements were information delivery and mediated organisational support and social influences. Multicomponent, information, and counselling interventions measuring total and/or occupational/nonoccupational SB time by self-report or via device-based measures were reported. Multicomponent interventions were the most represented. Eleven studies were included in the meta-analysis, which presented a reduction of 29.9 (95% CI: -45.2, -14.5) min/8 h workday in SB (overall effect: Z = 3.81).

CONCLUSIONS

Multicomponent interventions, using a wide range of digital features, have demonstrated effectiveness in reducing time spent in SB at the workplace among desk-based employees. However, due to hybrid work (i.e., work in the office and home) being a customary mode of work for many employees, it is important for future studies to assess the feasibility and effectiveness of these interventions in the evolving work landscape.

TRIAL REGISTRATION

The review protocol was registered in the Prospero database (CRD42022377366).

Concordance Between Accelerometer-Measured and Self-Reported Physical Activity and Sedentary Time in Adults with Autism

This study examined the concordance between accelerometry-measured and self-reported physical activity (PA) and sedentary time in adults with autism. Twenty-four participants wore an ActiGraph GT3X + accelerometer for seven consecutive days and completed the International Physical Activity Questionnaire-Short Form (IPAQ-SF) on the last day of their study participation. Bland-Altman plots assessed the magnitude of agreement between the two measures. Nearly 80% of the participants accumulated the recommended ≥ 150 min of moderate to vigorous PA (MVPA)/week, but were also sedentary for over nine hours/day according to accelerometry data. Findings showed that adults with autism tended to overreport MVPA (b = 1.606, p < 0.01) and underreport sedentary time (b = 1.161, p = 0.03) via the IPAQ-SF, as compared to objective measurements.

Reliability and validity of self-report questions for assessing levels of physical activity and sedentary time in adult childhood cancer survivors

BACKGROUND

Regular physical activity and limited sedentary time are recommended for adult childhood cancer survivors. The Swedish National Board of Health and Welfare designed a questionnaire to assess levels of physical activity (BHW-Q), including two questions: one on vigorous physical activity (BHW-Q VPA) and one on moderate physical activity (BHW-Q MPA). Furthermore, a single-item question was developed to measure sedentary time (SED-GIH-Q). These questions are recommended for clinical practice and have been found valid for the general population but have so far not been tested in adult childhood cancer survivors. The aim of the study was to assess test-retest reliability, agreement and criterion-related validity of the BHW-Q and the SED-GIH-Q in adult childhood cancer survivors.

METHOD

A non-experimental methodological study. In total 60 participants (50% women), median age 28 (min-max 18-54) years were included at the Long-Term Follow-Up Clinic at Sahlgrenska University Hospital. Participants were instructed to wear an accelerometer for seven days, and to answer the BHW-Q and the SED-GIH-Q before and after the seven days. Test-retest reliability and criterion-related validity comparing the BHW-Q and SED GIH-Q with accelerometer data were calculated with weighted Kappa (k) (agreement) and by using Spearman´s rho (r) (correlation).

RESULTS

Test-retest reliability regarding the SED-GIH-Q showed a high agreement (k = 0.88) and very strong correlation (r = 0.93), while the BHW-Q showed a moderate agreement and moderately strong correlation, BHW-Q VPA (k = 0.50, r = 0.64), BHW-Q MPA (k = 0.47, r = 0.58). Both the agreement and the correlation of the criterion-related validity were interpreted as fair for the BHW-Q VPA (k = 0.29, r = 0.45), while the agreement for BHW-Q MPA was interpreted as low (k = 0.07), but the correlation as fair (r = 0.37). The agreement of the SED-GIH-Q (k = 0.13) was interpreted as low and the correlation as poor (r = 0.26).

CONCLUSION

These simple questions assessing physical activity and sedentary time can be used as screening tools in clinical practice to identify adult childhood cancer survivors in need of support to increase physical activity level. Further development is needed on the design of a sufficiently valid question measuring sedentary time.

TRIAL REGISTRATION

This research project was registered in the Swedish National Database of Research and Development; identifier 275251, November 25, 2020. https://www.researchweb.org/is/vgr/project/275251 .

Joint association of sedentary behavior and physical activity with pulmonary function

BACKGROUND

Sedentary behavior may influence the respiratory health, but the joint effects of sedentary behavior and physical activity on pulmonary function remains poorly elucidated. We aimed to estimate the association between sedentary behavior and physical activity with pulmonary function.

METHODS

A total of 12,343 participants aged 12-79 years were analyzed from the U.S. NHANES 2007-2012. Participants were categorized into 16 groups according to the cross-tabulation of sedentary behavior time (0-4.0, 4.1-8.0, 8.1-12.0, and > 12.0 h/day) and moderate or vigorous physical activity (MVPA) (0, 1-149, 150-299, and ≥ 300 min/week). Generalized linear models were used to test the association of sedentary behavior and MVPA with pulmonary function.

RESULTS

Participants with sedentary behavior > 4.0 h/day were negatively related to FEV1 (forced expiratory volume in 1 s) (β ranging from -0.015 to -0.009, p < 0.05). Compared with the reference group (0 min of MVPA and > 12.0 h/day of sedentary behavior), the negative association of sedentary behavior ≤ 8.0 h/day with FEV1 may be reduced through appropriate MVPA (β ranging from 0.019 to 0.030, p < 0.05). For sedentary behavior > 8.0 h/day, even MVPA ≥ 300 min/week may not decrease the negative relationships. Similar results were also observed in FVC (forced vital capacity) (β ranging from 0.018 to 0.030, p < 0.05). In participants aged ≥ 45 years, the associations were more notable.

CONCLUSION

This study indicated the sedentary behavior ≤ 4.0 h/day was a relatively healthy lifestyle for pulmonary function. Only below 8.0 h/day of sedentary behavior, the negative association with pulmonary function may be reduced through appropriate MVPA.

StandUPTV: Preparation and optimization phases of a mHealth intervention to reduce sedentary screen time in adults

Recreational sedentary screen time (rSST) is the most prevalent sedentary behavior for adults outside of work, school, and sleep, and is strongly linked to poor health. StandUPTV is a mHealth trial that uses the Multiphase Optimization Strategy (MOST) framework to develop and evaluate the efficacy of three theory-based strategies for reducing rSST among adults. This paper describes the preparation and optimization phases of StandUPTV within the MOST framework. We identified three candidate components based on previous literature: (a) rSST electronic lockout (LOCKOUT), which restricts rSST through electronic means; (b) adaptive prompts (TEXT), which provides adaptive prompts based on rSST behaviors; and (c) earning rSST through increased moderate-vigorous physical activity (MVPA) participation (EARN). We also describe the mHealth iterative design process and the selection of an optimization objective. Finally, we describe the protocol of the optimization randomized controlled trial using a 23 factorial experimental design. We will enroll 240 individuals aged 23-64 y who engage in >3 h/day of rSST. All participants will receive a target to reduce rSST by 50% and be randomized to one of 8 combinations representing all components and component levels: LOCKOUT (yes vs. no), TEXT (yes vs. no), and EARN (yes vs. no). Results will support the selection of the components for the intervention package that meet the optimization objective and are acceptable to participants. The optimized intervention will be tested in a future evaluation randomized trial to examine reductions in rSST on health outcomes among adults.

Association of Sitting Time With All-Cause and Cardiovascular Mortality: How Does Frailty Modify This Association?

To investigate how frailty modifies the association of sitting time with all-cause and cardiovascular mortality in Chilean adults. This prospective study included 2,604 participants aged ≥35 from the Chilean National Health Survey 2009-2010. Sitting time was self-reported, while frailty was assessed using a 36-item Frailty Index. Sitting time was categorized as low, medium, and high. Cox proportional hazard models were used to estimate the risk of mortality stratified for the sitting time categories. Over a median follow-up of 8.9 years, 311 participants died, 28% of them due to cardiovascular events. Frail people with prolonged sitting time were at higher risk of all-cause and cardiovascular mortality (hazard ratio 3.13; 95% confidence interval [2.06, 4.71] and hazard ratio 2.41; 95% confidence interval [1.50, 3.64], respectively). The observed risk was higher in women than men. Public health and individual strategies should be implemented to decrease sitting time across the population, with special attention on frail people.

Comparative analysis of temporal trends of obesity and physical inactivity in Brazil and the USA (2011-2021)

BACKGROUND

The prevalence of obesity is rising in all subregions of America, including Brazil. To understand the obesity problem in Brazil better, a possible approach could be to analyze its obesity trend by comparing it with the reality of a country that went previously through the epidemiological transition, such as the USA. In addition, the obesity trend must be analyzed in comparison with obesity risk factors trends, such as the physical inactivity (PI) trend. Our aim was comparatively to analyze the temporal trends of obesity between Brazil and the USA from the perspective of temporal trends of PI.

METHODS

We conducted a temporal trend study based on data from national cross-sectional surveys: the VIGITEL (Surveillance System for Factors of Health Risk and Protection for Chronic Diseases by Telephone Survey) for Brazil and the BRFSS (Behavioral Risk Factor Surveillance System) for the USA, comparing the annual prevalence of obesity and PI between 2011 and 2021. For the analysis of each temporal variation, linear regressions were performed with the Prais-Winsten test, and Pearson's correlation coefficient was conducted to correlate the trends of the same variables between countries and of different variables within each country.

RESULTS

Considering the total sample, Brazil [coefficient (95%CI) 0.6 (0.4;0.7), p = 0.000] and the USA [coefficient (95%CI) 0.5 (0.5;0.6), p = 0.000] showed increasing trends in obesity. The tendency of PI was of stabilization in the two countries [Brazil: coefficient (95%CI) -0.03 (-0.3;0.2), p = 0.767 and USA coefficient (95%CI) -0.03 (-0.2;0.1), p = 0.584]. In addition, there was a correlation between obesity trends between Brazil and the USA (r = 0.971; p = 0.000), but there was no correlation between PI trends between the two countries, nor with obesity and PI trends within each country.

CONCLUSIONS

In the last decade, there was a trend towards increasing obesity and stabilization in PI, both in Brazil and the USA. However, there was no association between temporal trends in obesity and physical inactivity in both countries. Our data reinforce a call to action to prevent and control obesity, going with and beyond PI reduction.

Sitting vs. standing: an urgent need to rebalance our world

During their activities of daily living, humans run, walk, stand, sit and lie down. Recent changes in our environment have favored sedentary behavior over more physically active behavior to such a degree that our health is in danger. Here, we sought to address the problem of excessive time spent seated from various theoretical viewpoints, including postural control, human factors engineering, human history and health psychology. If nothing is done now, the high prevalence of sitting will continue to increase. We make a case for the standing position by demonstrating that spending more time upright can mitigate the physiological and psychological problems associated with excessive sitting without lowering task performance and productivity. The psychological literature even highlights potential benefits of performing certain tasks in the standing position. We propose a number of recommendations on spending more time (but not too much) in the standing position and on more active, nonambulatory behaviors. There is a need to inform people about (i) harmful consequences of excessive sitting and (ii) benefits of spending more time performing active, nonambulatory behaviors. One clear benefit is to reduce detrimental health consequences of excessive sitting and to provide potential additional benefits in terms of productivity and performance.

Sedentary time is associated with depressive symptoms and state anxiety in women with fibromyalgia. Could physical activity and fitness modify this association? The al-Ándalus project

PURPOSE

To analyze the associations of total and prolonged sedentary time (ST) with depressive symptoms and state anxiety in women with fibromyalgia and whether these associations are modified by moderate-to-vigorous physical activity (MVPA) and physical fitness.

METHODS

This cross-sectional exploratory study included 386 women with fibromyalgia aged 51.2 ± 7.6 years. Total ST, time in prolonged bouts of ST (≥30- and ≥60-min) and MVPA were measured with triaxial accelerometry. Depressive symptoms were assessed with the "Beck Depression Inventory-second edition," state anxiety with the "State-Trait Anxiety Inventory," and physical fitness with the "Senior Fitness Test Battery."

RESULTS

Total and prolonged ST were directly associated with depressive symptoms (total: β = 0.19, ≥30-min bout: β = 0.15, and ≥60-min bout: β = 0.12) and odds of severe depressive symptoms (all, p < 0.001). These associations generally remained significant after adjustments for MVPA and physical fitness (all, p < 0.05). Total and prolonged ST were directly associated with state anxiety (total: β = 0.11, ≥30-min bout: β = 0.12, and ≥60-min bout: β = 0.07; all, p < 0.001). These associations were generally independent of MVPA (p < 0.05) but vanished when considering physical fitness (p > 0.05).

CONCLUSIONS

Higher levels of total and prolonged ST are associated with greater depressive symptoms and state anxiety in women with fibromyalgia. MVPA did not modify these associations, although physical fitness could play a protective role specially for state anxiety.IMPLICATIONS FOR REHABILITATIONReducing sedentary time and avoiding its accumulation in prolonged periods could potentially reduce depressive symptoms and state anxiety in fibromyalgia.Higher sedentary time is associated with more severe depressive symptoms even in patients who engage in moderate-to-vigorous physical activity.Higher levels of physical fitness could attenuate the negative associations of sedentary time with depressive symptoms and, specially, state anxiety."Sit less, move more and exercise to increase your fitness" could be a positive message for people with fibromyalgia in clinical settings.

The effects of a 6-month intervention aimed to reduce sedentary time on skeletal muscle insulin sensitivity: a randomized controlled trial

Sedentary behavior (SB) and physical inactivity associate with impaired insulin sensitivity. We investigated whether an intervention aimed at a 1-h reduction in daily SB during 6 mo would improve insulin sensitivity in the weight-bearing thigh muscles. Forty-four sedentary inactive adults [mean age 58 (SD 7) yr; 43% men] with metabolic syndrome were randomized into intervention and control groups. The individualized behavioral intervention was supported by an interactive accelerometer and a mobile application. SB, measured with hip-worn accelerometers in 6-s intervals throughout the 6-mo intervention, decreased by 51 (95% CI 22-80) min/day and physical activity (PA) increased by 37 (95% CI 18-55) min/day in the intervention group with nonsignificant changes in these outcomes in the control group. Insulin sensitivity in the whole body and in the quadriceps femoris and hamstring muscles, measured with hyperinsulinemic-euglycemic clamp combined with [18F]fluoro-deoxy-glucose PET, did not significantly change during the intervention in either group. However, the changes in hamstring and whole body insulin sensitivity correlated inversely with the change in SB and positively with the changes in moderate-to-vigorous PA and daily steps. In conclusion, these results suggest that the more the participants were able to reduce their SB, the more their individual insulin sensitivity increased in the whole body and in the hamstring muscles but not in quadriceps femoris. However, according to our primary randomized controlled trial results, this kind of behavioral interventions targeted to reduce sedentariness may not be effective in increasing skeletal muscle and whole body insulin sensitivity in people with metabolic syndrome at the population level.NEW & NOTEWORTHY Aiming to reduce daily SB by 1 h/day had no impact on skeletal muscle insulin sensitivity in the weight-bearing thigh muscles. However, successfully reducing SB may increase insulin sensitivity in the postural hamstring muscles. This emphasizes the importance of both reducing SB and increasing moderate-to-vigorous physical activity to improve insulin sensitivity in functionally different muscles of the body and thus induce a more comprehensive change in insulin sensitivity in the whole body.

Leisure sedentary behaviour increases the risk of venous thromboembolism: a Mendelian randomisation study

BACKGROUND

Venous thromboembolism (VTE) is a substantial contributor to the global burden of disease. Observational studies have suggested that leisure sedentary behaviours (LSB) are related to the risk of VTE; however, the causal role of LSB in VTE remains unclear.

METHODS

Using data obtained from genome-wide association studies in the UK Biobank (N = 422,218), we identified 84, 21, and 4 single nucleotide polymorphisms (SNPs) related to sedentary television (TV) watching, computer use, and driving, respectively. These SNPs were employed as instrumental variables. Summary statistics for SNP-VTE associations was obtained from the FinnGen study (5,403 cases and 130,235 controls). Two-sample Mendelian randomisation (MR) analyses were performed using inverse-variance weighted (IVW), MR-Egger,weighted median, and weighted mode approaches. Sensitivity analyses were conducted to ensure robustness of the results.

RESULTS

The main IVW approach demonstrated a positive association between the genetically predicted sedentary TV watching and the risk of VTE [odds ratio (OR):1.35, 95% confidence interval (CI):1.02-1.80, P = 0.039]. However, no significant association was observed for genetically predicted sedentary computer use or driving and VTE risk. The results from our series of sensitivity analyses, including Cochran's Q test, MR-Egger intercept test, and MR-Pleiotropy RESidual Sum and Outlier method, further supported these findings.

CONCLUSION

This study provides evidence of an association between genetically predicted sedentary TV watching and the risk of VTE. Further studies are required to elucidate the underlying causal mechanisms.

Do associations of physical activity and sedentary behaviour with cardiovascular disease and mortality differ across socioeconomic groups? A prospective analysis of device-measured and self-reported UK Biobank data

OBJECTIVE

To examine if individual-level and area-level socioeconomic status (SES) modifies the association of moderate-to-vigorous physical activity (MVPA), domain-specific physical activity and sedentary behaviour with all-cause mortality (ACM) and incident cardiovascular disease (CVD).

METHODS

We used self-reported (International Physical Activity Questionnaire short form) and accelerometer-measured physical activity and sedentary behaviour data from the UK Biobank. We created an individual-level composite SES index using latent class analysis of household income, education and employment status. The Townsend Index was the measure of area-level SES. Cox proportional hazards regression models stratified across SES were used.

RESULTS

In 328 228 participants (mean age 55.9 (SD 8.1) years, 45% men) with an average follow-up of 12.1 (1.4) years, 18 033 deaths and 98 922 incident CVD events occurred. We found an increased ACM risk of low physical activity and high sedentary behaviour and an increased incident CVD risk of low accelerometer-measured moderate-to-vigorous physical activity (ACCEL_MVPA) and high sitting time. We observed statistically significant interactions for all exposures in ACM analyses by individual-level SES (p<0.05) but only for screen time in area-level SES-ACM analysis (p<0.001). Compared with high self-reported moderate-to-vigorous physical activity (IPAQ_MVPA), adjusted ACM HRs for low IPAQ_MVPA were 1.14 (95% CI 1.05 to .25), 1.15 (95% CI 1.06 to 1.24) and 1.22 (95% CI 1.13 to 1.31) in high, medium and low individual-level SES, respectively. There were higher detrimental associations of low ACCEL_MVPA with decreasing area-level SES for both outcomes and of high screen time with ACM in low area-level SES.

CONCLUSION

We found modest evidence suggesting that the detrimental associations of low MVPA and high screen time with ACM and incident CVD are accentuated in low SES groups.

Systematic review and meta-analysis of the effectiveness of chatbots on lifestyle behaviours

Chatbots (also known as conversational agents and virtual assistants) offer the potential to deliver healthcare in an efficient, appealing and personalised manner. The purpose of this systematic review and meta-analysis was to evaluate the efficacy of chatbot interventions designed to improve physical activity, diet and sleep. Electronic databases were searched for randomised and non-randomised controlled trials, and pre-post trials that evaluated chatbot interventions targeting physical activity, diet and/or sleep, published before 1 September 2022. Outcomes were total physical activity, steps, moderate-to-vigorous physical activity (MVPA), fruit and vegetable consumption, sleep quality and sleep duration. Standardised mean differences (SMD) were calculated to compare intervention effects. Subgroup analyses were conducted to assess chatbot type, intervention type, duration, output and use of artificial intelligence. Risk of bias was assessed using the Effective Public Health Practice Project Quality Assessment tool. Nineteen trials were included. Sample sizes ranged between 25-958, and mean participant age ranged between 9-71 years. Most interventions (n = 15, 79%) targeted physical activity, and most trials had a low-quality rating (n = 14, 74%). Meta-analysis results showed significant effects (all p < 0.05) of chatbots for increasing total physical activity (SMD = 0.28 [95% CI = 0.16, 0.40]), daily steps (SMD = 0.28 [95% CI = 0.17, 0.39]), MVPA (SMD = 0.53 [95% CI = 0.24, 0.83]), fruit and vegetable consumption (SMD = 0.59 [95% CI = 0.25, 0.93]), sleep duration (SMD = 0.44 [95% CI = 0.32, 0.55]) and sleep quality (SMD = 0.50 [95% CI = 0.09, 0.90]). Subgroup analyses showed that text-based, and artificial intelligence chatbots were more efficacious than speech/voice chatbots for fruit and vegetable consumption, and multicomponent interventions were more efficacious than chatbot-only interventions for sleep duration and sleep quality (all p < 0.05). Findings from this systematic review and meta-analysis indicate that chatbot interventions are efficacious for increasing physical activity, fruit and vegetable consumption, sleep duration and sleep quality. Chatbot interventions were efficacious across a range of populations and age groups, with both short- and longer-term interventions, and chatbot only and multicomponent interventions being efficacious.

Joint Association between Sedentary Time and Moderate-to-Vigorous Physical Activity with Obesity Risk in Adults from Latin America

Recent studies have shown various relationships between physical activity and the incidence of obesity, but this study critically explored the association of sedentary time (ST) and moderate-to-vigorous physical activity (MVPA) with obesity risk in adults from eight Latin American countries. ST and MVPA were assessed with accelerometers and stratified into 16 joint categories. Multivariate logistic regression models were used. The obesity risk indicators evaluated were body mass index (BMI), waist circumference (WC), and neck circumference (NC). Quartile 4 of ST and ≥300 min/week of MVPA was associated with lower odds of BMI compared to quartile 1 of ST and ≥300 min/week of MVPA. Quartile 1 of ST and 150-299 min/week of MVPA, quartile 1 of ST and 76-149 min/week MVPA, quartile 3 of ST and 76-149 min/week MVPA, and quartiles 1, 2, and 3 of ST with 0-74 min/week MVPA were associated with higher odds of high WC compared to quartile 1 of ST and ≥300 min/week of MVPA. Quartile 3 of ST and 150-299 min/week of MVPA, quartiles 1 and 3 of ST and 76-149 min/week of MVPA, and quartile 1 of ST and 0-74 min/week MVPA were associated with higher NC compared to quartile 1 of ST and ≥300 min/week of MVPA. This study suggests that achieving the MVPA recommendations will likely protect against obesity, regardless of ST.

A Review of Sedentary Behavior Assessment in National Surveillance Systems

BACKGROUND

Temporal changes in sedentary behavior patterns reflect the evolving nature of our built and social environments, particularly the expanding availability of electronic media. It is important to understand what types of sedentary behavior are assessed in national surveillance to determine whether, and to what extent, they reflect contemporary patterns. The aims of this review were to describe the characteristics of questionnaires used for national surveillance of sedentary behavior and to identify the types of sedentary behaviors being measured.

METHOD

We reviewed questionnaires from national surveillance systems listed on the Global Observatory for Physical Activity (GoPA!) country cards to locate items on sedentary behavior. Questionnaire characteristics were categorized using the Taxonomy of Self-reported Sedentary Behavior Tools (TASST). The purpose and type of sedentary behaviors captured were classified using the Sedentary Behavior International Taxonomy (SIT).

RESULTS

Overall, 346 surveillance systems were screened for eligibility, of which 93 were included in this review. Most questionnaires used a single-item direct measure of sitting time (n = 78, 84%). Work and domestic were the most frequently captured purposes of sedentary behavior, while television viewing and computer use were the most frequently captured types of behaviors.

CONCLUSION

National surveillance systems should be periodically reviewed in response to evidence on contemporary behavior patterns in the population and the release of updated public health guidelines.

Associations of accelerometer-based sedentary bouts with adiposity markers among German adults - results from a cross-sectional study

BACKGROUND

Long periods of uninterrupted sitting, i.e., sedentary bouts, and their relationship with adverse health outcomes have moved into focus of public health recommendations. However, evidence on associations between sedentary bouts and adiposity markers is limited. Our aim was to investigate associations of the daily number of sedentary bouts with waist circumference (WC) and body mass index (BMI) in a sample of middle-aged to older adults.

METHODS

In this cross-sectional study, data were collected from three different studies that took place in the area of Greifswald, Northern Germany, between 2012 and 2018. In total, 460 adults from the general population aged 40 to 75 years and without known cardiovascular disease wore tri-axial accelerometers (ActiGraph Model GT3X+, Pensacola, FL) on the hip for seven consecutive days. A wear time of ≥ 10 h on ≥ 4 days was required for analyses. WC (cm) and BMI (kg m^- 2) were measured in a standardized way. Separate multilevel mixed-effects linear regression analyses were used to investigate associations of sedentary bouts (1 to 10 min, >10 to 30 min, and >30 min) with WC and BMI. Models were adjusted for potential confounders including sex, age, school education, employment, current smoking, season of data collection, and composition of accelerometer-based time use.

RESULTS

Participants (66% females) were on average 57.1 (standard deviation, SD 8.5) years old and 36% had a school education >10 years. The mean number of sedentary bouts per day was 95.1 (SD 25.0) for 1-to-10-minute bouts, 13.3 (SD 3.4) for >10-to-30-minute bouts and 3.5 (SD 1.9) for >30-minute bouts. Mean WC was 91.1 cm (SD 12.3) and mean BMI was 26.9 kg m^- 2 (SD 3.8). The daily number of 1-to-10-minute bouts was inversely associated with BMI (b = -0.027; p = 0.047) and the daily number of >30-minute bouts was positively associated with WC (b = 0.330; p = 0.001). All other associations were not statistically significant.

CONCLUSION

The findings provide some evidence on favourable associations of short sedentary bouts as well as unfavourable associations of long sedentary bouts with adiposity markers. Our results may contribute to a growing body of literature that can help to define public health recommendations for interrupting prolonged sedentary periods.

TRIAL REGISTRATION

Study 1: German Clinical Trials Register (DRKS00010996); study 2: ClinicalTrials.gov (NCT02990039); study 3: ClinicalTrials.gov (NCT03539237).

The effect of time spent sitting and excessive gaming on the weight status, and perceived weight stigma among Taiwanese young adults

Background

During the COVID-19 pandemic, physical inactivity and sedentary behaviors (i.e., longer sitting time and excessive gaming) increased because governments across the globe adopted stringent mitigation strategies such as social distancing and lockdowns to curb the spread of the virus. Excessive gaming was one of the coping mechanisms used to deal with the pressure associated with the pandemic. Moreover, perceived weight stigma (PWS) and weight status became more salient concerns among young adults during the COVID-19 pandemic. The current study sought to investigate the relationship between time spent sitting, excessive gaming, weight status, and PWS of Taiwanese Young adults. Additionally, weight status and PWS were examined as mediators between both sedentary behaviors.

Methods

This cross-sectional study involved 600 participants who were recruited through Taiwan universities. All participants completed a demographic questionnaire (including weight and height) and self-report measures including the International Physical Activity Questionnaire short form (IPAQ-SF), the Perceived Weight Stigma Scale (PWSS), and the Internet Gaming Disorder Scale-short form (IGDS9-SF). PROCESS model was performed to test the potential mediation roles of weight status and PWS. Moreover, we categorized participants into two groups based on the sitting-time item in the IPAQ-SF: students whose sitting time was less than 8 h daily, and those more than 8 h daily.

Results

The group that had less than 8 h had significantly higher PWS and IGDS9-SF scores than the other group. Sitting time was negatively associated with weight status, PWS, and IGDS9-SF. Additionally, we found a significantly direct effect between time spent sitting and excessive gaming. Both weight status and PWS were significant mediators in the association between time spent sitting and excessive gaming.Conclusions: The present study demonstrated important negative correlates of excessive sedentary behaviors. Prevention efforts should focus on promoting physical activity and providing information to decrease sedentary behavior among university students.

Timing of physical activity in relation to liver fat content and insulin resistance

AIMS/HYPOTHESIS

We hypothesised that the insulin-sensitising effect of physical activity depends on the timing of the activity. Here, we examined cross-sectional associations of breaks in sedentary time and timing of physical activity with liver fat content and insulin resistance in a Dutch cohort.

METHODS

In 775 participants of the Netherlands Epidemiology of Obesity (NEO) study, we assessed sedentary time, breaks in sedentary time and different intensities of physical activity using activity sensors, and liver fat content by magnetic resonance spectroscopy (n=256). Participants were categorised as being most active in the morning (06:00-12:00 hours), afternoon (12:00-18:00 hours) or evening (18:00-00:00 hours) or as engaging in moderate-to-vigorous-physical activity (MVPA) evenly distributed throughout the day. Most active in a certain time block was defined as spending the majority (%) of total daily MVPA in that block. We examined associations between sedentary time, breaks and timing of MVPA with liver fat content and HOMA-IR using linear regression analyses, adjusted for demographic and lifestyle factors including total body fat. Associations of timing of MVPA were additionally adjusted for total MVPA.

RESULTS

The participants (42% men) had a mean (SD) age of 56 (4) years and a mean (SD) BMI of 26.2 (4.1) kg/m². Total sedentary time was not associated with liver fat content or insulin resistance, whereas the amount of breaks in sedentary time was associated with higher liver fat content. Total MVPA (-5%/h [95% CI -10%/h, 0%/h]) and timing of MVPA were associated with reduced insulin resistance but not with liver fat content. Compared with participants who had an even distribution of MVPA throughout the day, insulin resistance was similar (-3% [95% CI -25%, 16%]) in those most active in morning, whereas it was reduced in participants who were most active in the afternoon (-18% [95% CI -33%, -2%]) or evening (-25% [95% CI -49%, -4%]).

CONCLUSIONS/INTERPRETATION

The number of daily breaks in sedentary time was not associated with lower liver fat content or reduced insulin resistance. Moderate-to-vigorous activity in the afternoon or evening was associated with a reduction of up to 25% in insulin resistance. Further studies should assess whether timing of physical activity is also important for the occurrence of type 2 diabetes.

Reducing Sedentary Time and Whole-Body Insulin Sensitivity in Metabolic Syndrome: A 6-Month Randomized Controlled Trial

PURPOSE

This study aimed to investigate whether a reduction in daily sedentary behavior (SB) improves insulin sensitivity in adults with metabolic syndrome in 6 months, without adding intentional exercise training.

METHODS

Sixty-four sedentary inactive middle-age adults with overweight and metabolic syndrome (mean (SD) age, 58 (7) yr; mean (SD) body mass index, 31.6 (4.3) kg·m -2 ; 27 men) were randomized into intervention and control groups. The 6-month individualized behavioral intervention supported by an interactive accelerometer and a mobile application aimed at reducing daily SB by 1 h compared with baseline. Insulin sensitivity by hyperinsulinemic euglycemic clamp, body composition by air displacement plethysmography, and fasting blood samples were analyzed before and after the intervention. SB and physical activity were measured with hip-worn accelerometers throughout the intervention.

RESULTS

SB decreased by 40 (95% confidence interval, 17-65) min·d -1 , and moderate-to-vigorous physical activity increased by 20 (95% confidence interval, 11-28) min·d -1 on average in the intervention group with no significant changes in these outcomes in the control group. After 6 months, fasting plasma insulin decreased (~1 mU·L -1 ) in the intervention group compared with the control group (time-group, P = 0.0081), but insulin sensitivity did not change in either group. The changes in body mass or adiposity did not differ between groups. Among all participants, the changes in SB and body mass correlated inversely with the change in insulin sensitivity ( r = -0.31, -0.44; P = 0.025, 0.0005, respectively).

CONCLUSIONS

An intervention aimed at reducing daily SB resulted in slightly decreased fasting insulin, but had no effects on insulin sensitivity or body adiposity. However, as the change in insulin sensitivity associated with the changes in SB and body mass, multifaceted interventions targeting to weight loss are likely to be beneficial in improving whole-body insulin sensitivity.

Validity and Accuracy of Step Count as an Indicator of a Sedentary Lifestyle in People With Chronic Obstructive Pulmonary Disease

OBJECTIVE

To determine the validity and accuracy of <5000 steps/day as a sedentary lifestyle indicator, and the optimal step count cut point value for indicating a sedentary lifestyle in people with chronic obstructive pulmonary disease (COPD).

DESIGN

Analysis of baseline data from a randomized clinical trial.

SETTING

Sydney, Australia.

PARTICIPANTS

Stable COPD on the waitlist for pulmonary rehabilitation.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Step count and time in sedentary behavior (SB) were assessed using thigh-worn accelerometry. A sedentary lifestyle was defined as <5000 steps/day. Pearson correlation coefficients were analyzed between step count and time spent in SB. Sensitivity, specificity, and accuracy were calculated for the <5000 steps/day threshold. Receiver operating characteristic curves with the area under the curve were computed for step count in identifying a sedentary lifestyle.

RESULTS

69 people with COPD (mean age=74 years, SD=9; forced expiratory volume in 1 second, mean=55%, SD=19 predicted) had sufficient wear data for analysis. There was a moderate inverse correlation between step count and time spent in SB (r=-0.58, P<.001). Step count had a fair discriminative ability for identifying a sedentary lifestyle (area under the curve=0.80, 95% confidence interval [CI], 0.68-0.91). The <5000 steps/day threshold had a sensitivity, specificity, and accuracy of 82% (95% CI, 70-94), 70% (95% CI, 54-86), and 78%, respectively. A lower threshold of <4300 steps/day was more accurate for ruling in a sedentary lifestyle.

CONCLUSIONS

Compared with thigh-worn accelerometry, <5000 steps/day is a valid and reasonably accurate indicator of a sedentary lifestyle in this population.

Association between sedentary behavior and chronic kidney disease in Korean adults

BACKGROUND

Chronic kidney disease (CKD) is a significant health care burden, with a worldwide prevalence of approximately 11%. The general population spends over 50% of the awake time sedentary activities. However, to the best of our knowledge, no study has evaluated the association between sedentary time and CKD, with a focus on both kidney damage and kidney function, in the South Korean population. Accordingly, the present study aimed to address this gap in the knowledge.

METHOD

We used data from the 8^th Korea National Health and Nutrition Examination Survey. The analysis included 9,534 participants, especially excluded those who had been diagnosed with kidney disease or who were currently undergoing treatment. Sedentary behavior was self-reported by the participants. An estimated glomerular filtration rate (eGFR) and/or albuminuria were used as measures for detection of CKD according to the guidelines of the Kidney Disease Improving Global Outcomes. We analyzed the data using multiple logistic regression.

RESULTS

Among the women, the risk of CKD was significantly greater among those who sat for ≥ 12 h/d relative to those who sat for < 6 h/d, after adjusting for physical activity and other covariates (odds ratio [OR]: 1.45, 95% confidence interval [CI]: 1.01-2.06). Similarly, among those who sat over 12 h/d, those who engaged in low levels of physical activity had a higher risk of CKD than those who engaged in high levels of activity (OR: 1.65, 95% CI: 1.04-2.61). No statistically significant results were found for men.

CONCLUSION

Excessive sedentary behavior was associated with an increased risk of CKD, especially albuminuria, regardless of the level of physical activity, only in women. These findings emphasize the importance of avoiding excessive sitting for a long time and increasing overall physical activity levels.

The Joint Associations of Physical Activity and Sedentary Behaviors on Adiposity during Adolescence: The 1993 Pelotas (Brazil) Cohort Study

A prior study conducted in high-income countries demonstrated that specific sedentary behavior, such as TV viewing, is prospectively associated with adiposity in both active and inactive adolescents. The aim of this study was to examine the joint associations of sedentary behaviors and moderate- and vigorous-intensity physical activity (MVPA) with adiposity among Brazilian adolescents. This prospective cohort study included 377 participants of the 1993 Pelotas (Brazil) Study who completed an accelerometry assessment at age 13 years and a dual-energy X-ray absorptiometry (DXA) assessment at age 18 years. Accelerometer-measured MVPA was dichotomized into high (≥60 min/day) and low (<60 min/day). Accelerometer-measured sedentary time (SED) was dichotomized into low (<49 min/h) and high (≥49 min/h) based on the median. Self-reported TV viewing time was also dichotomized into low (<3 h/day) and high (≥3 h/day) based on the median. We combined the two MVPA groups (high and low) and two SED groups (low and high) to form the four MVPA&SED groups: high&low, high&high, low&low, and low&high. We also created four MVPA&TV groups in the same manner. Fat mass index (FMI; kg/m2) was calculated using DXA-derived fat mass. Multivariable linear regression analyses compared FMI at 18 years among the four MVPA&SED groups and among the four MVPA&TV groups, adjusting for socioeconomic status, energy intake, and baseline adiposity. The analysis results showed that SED or TV viewing time was not prospectively associated with adiposity in both active and inactive Brazilian adolescents. This study suggests that the association between specific sedentary behaviors, such as TV viewing, and adiposity may differ across societal settings-in this case, high-income vs. middle-income countries.

Accelerometer-derived physical activity and sedentary behaviors in individuals with newly diagnosed type 2 diabetes: A cross-sectional study from the Danish nationwide DD2 cohort

Introduction

Habitual physical activity behaviors of individuals with new-onset type 2 diabetes are largely unknown. We aimed to investigate accelerometer-derived physical activity behaviors in individuals with newly diagnosed type 2 diabetes. We also examined sociodemographic and health-related correlates of a high-risk physical activity profile.

Methods

This cross-sectional study used data from 768 participants enrolled in an intervention study nested within the Danish Centre for Strategic Research in Type 2 diabetes (DD2) cohort. Physical activity was assessed by 24-h dual monitor accelerometry. Prevalence ratios of having a high-risk physical activity profile were estimated using Poisson regression adjusted for age and sex.

Results

Study participants spent on average 9.7 (25th and 75th percentiles, 8.3; 11.1) hours/day sitting, walked for 1.1 (0.8; 1.6) hours/day and accumulated 4,000 (2,521; 5,864) steps/day. Still, 62% met the recommendations for physical activity. Characteristics associated with a high-risk physical activity profile (observed in 24.5% of participants) included older age, higher body mass index (BMI), unemployment, retirement, comorbidities, and current smoking. Hence, participants aged 60-69, 70-79 and 80+ years had prevalence ratios of 2.12 (95% CI 1.31; 3.42), 1.99 (1.18; 3.34) and 3.09 (1.42; 6.75) for a high-risk activity profile, respectively, versus participants <50 years. BMI values of 30-39 and 40+ were associated with 1.83 (1.06; 3.15) and 3.38 (1.88; 6.05) higher prevalence ratios compared to normal-weight. Unemployment or retirement was associated with 1.62 (1.09; 2.41) and 2.15 (1.37; 3.39) times higher prevalence ratios, compared to individuals in the working force. Having a Charlson Comorbidity Index score of 1-2 or 3+ was associated with 1.36 (1.03-1.79) and 1.90 (1.27-1.84) higher prevalence ratios, while current smoking was associated with a prevalence ratio of 1.72 (1.25; 2.35) compared to never smokers.

Conclusion

This study shows that 62% of individuals with newly diagnosed type 2 diabetes met the recommendations for physical activity. Still, the majority of participants were also highly sedentary and accumulated very few daily steps, emphasizing the need for focusing on both increasing physical activity and reducing sedentary behaviors in the prevention of diabetes-related complications. Individuals with a high-risk physical activity profile were characterized by more obesity, socioeconomic inequalities, advanced age and comorbidities.Trial registration number: NCT02015130.

Does a break from sitting change biomechanical outcome measures or transient pain? A laboratory-based experimental study

BACKGROUND

Sitting can induce transient low back pain (LBP) in healthy individuals. A rest from sitting should provide relief, however, the parameters of breaks (activity type, intensity, duration, and timing) are not currently known.

OBJECTIVE

The purpose of this study was to examine the effect of 2-minute walking breaks at 40-minute intervals on sitting-induced LBP.

METHODS

Thirty-two healthy participants were recruited for a within-control study: two randomly presented sessions of sitting for 2 hours with and without breaks. Outcome measures were compared between condition and pain group using a three-way ANOVA with significance atp > 0.05.

RESULTS

Walking breaks at 40-minute intervals result in significantly lower pain ratings than those taken immediately before the break for sitting-induced back pain developers. However, this relief is short lived (<10 minutes), with ratings increasing to pre-break levels once the sitting exposure resumes. There were no differences in biomechanical factors between sessions. Regardless of session type, pain developers displayed higher spine fidget frequency than non-pain developers, females sat with less spine flexion, with greater gluteal activation levels, and with their center of pressure approximately half a centimeter to the left and forward compared to males, and males had significantly greater peak pressures over a smaller area compared to females.

CONCLUSION

Walking breaks at 40-minute intervals provide significant, but temporary, relief of sitting-induced back pain for pain developers. Future work should optimize break parameters and examine the longer-term benefit of breaks, especially for individuals that are not able to tolerate sitting for extended durations.

Characterization of Detailed Sedentary Postures Using a Tri-Monitor ActivPAL Configuration in Free-Living Conditions

Objective monitors such as the activPAL characterize time when the thigh is horizontal as sedentary time. However, there are physiological differences between lying, bent-legged sitting, and straight-legged sitting. We introduce a three-monitor configuration to assess detailed sedentary postures and demonstrate its use in characterizing such positions in free-living conditions. We explored time spent in each sedentary posture between prolonged (>1 h) versus non-prolonged (<1 h) sedentary bouts. In total, 35 healthy adults (16♀, 24 ± 3 years; 24 h/day for 6.8 ± 1.0 days) wore an activPAL accelerometer on their thigh, torso, and shin. Hip and knee joint flexion angle estimates were determined during sedentary bouts using the dot-product method between the torso−thigh and thigh−shin, respectively. Compared to lying (69 ± 60 min/day) or straight-legged sitting (113 ± 100 min/day), most time was spent in bent-legged sitting (439 ± 101 min/day, p < 0.001). Most of the bent-legged sitting time was accumulated in non-prolonged bouts (328 ± 83 vs. 112 ± 63 min/day, p < 0.001). In contrast, similar time was spent in straight-legged sitting and lying between prolonged/non-prolonged bouts (both, p > 0.26). We document that a considerable amount of waking time is accumulated in lying or straight-legged sitting. This methodological approach equips researchers with a means of characterizing detailed sedentary postures in uncontrolled conditions and may help answer novel research questions on sedentariness.

Examining the Dose-Response Relationship between Physical Activity and Health Outcomes

Physical Activity and Health and LongevityPhysical activity is a powerful tool to improve health. This article reviews the evidence supporting a relationship between physical activity and health outcomes, including mortality, and discusses the optimal dose of physical activity.

Public Health Concern on Sedentary Behavior and Cardiovascular Disease: A Bibliometric Analysis of Literature from 1990 to 2022

Background and Objectives: Cardiovascular disease is a long-term threat to global public health security, while sedentary behavior is a modifiable behavior among cardiovascular risk factors. This study aimed to analyze the peer-reviewed literature published globally on sedentary behavior and cardiovascular disease (SB-CVD) and identify the hotspots and frontiers within this research area. Materials and Methods: Publications on SB-CVD from 1990 to 2022 were retrieved from the Web of Science Core Collection. CiteSpace and VOSviewer were applied to perform bibliometric and knowledge mapping visualization analyses. Results: A total of 2071 publications were retrieved, presenting a gradual growing trend. Authors from the USA topped the list with 748 (36.12%), followed by authors from England (373, 18.01%) and Australia (354, 17.09%). The University of Queensland, Australia, led with 95 (4.5%) publications. The top five active authors were all from Australia, while Dunstan D and Owen N published the most documents (56, 2.7%). A total of 71.27% of the publications received funding, and the United States Department of Health and Human Services provided 363 (17.53%) grants. Public Environmental Occupational Health (498, 24.05%), Sport Sciences (237, 11.44%), and Cardiac Cardiovascular Systems (212, 10.24%) were the three most popular disciplines, while PLOS One (96, 4.64%) and BMC Public Health (88, 4.25%) were the two most popular journals. Investigations within the SB-CVD research area addressed the entire lifespan, the most popular type of research was the epidemiological study, and the accelerometer was the primary instrument for measuring sedentary behavior. In terms of variables, physical activity and sedentary behavior were the dominant lifestyle behaviors, while obesity and hypertension were common health problems. Occupational physical activity and guidelines are at the frontier and are currently in the burst stage. Conclusions: The last three decades have witnessed the rapid development of the SB-CVD research area, and this study provided further research ideas for subsequent investigations.

Desk based prompts to replace workplace sitting with stair climbing; a pilot study of acceptability, effects on behaviour and disease risk factors

Background

Prolonged sitting is associated with increased risk of obesity, type 2 diabetes and cardiovascular disease. Occupational sitting accounts for up to 50 h/week for employees. This pilot study assessed the acceptability of stair climbing as an interruption to sitting throughout working hours, and provided preliminary data of the effects on glucose and lipid profiles.

Methods

A quasi-experimental design was conducted involving 16 sedentary office workers (five females and 11 males) for intervention (n = 8) and control groups (n = 8) with mean age of 36.38 (5.58). For the eight-week intervention, a continuous four-floor stair climb and descent was performed eight times/day spread evenly over the working day. A prompt to climb was presented on the participant’s computer eight times/day. Participants in the experimental group recorded daily floors climbed and steps (measured using pedometers) in a weekly log sheet. Blood samples were collected pre and post intervention to test effects on fasting glucose and 2 h plasma glucose, triglycerides, and total (TC), LDL and HDL cholesterol. Experimental participants were interviewed at the end of the study. The Wilcoxon signed rank test was used to compare the median changes (pre-post) of the dependent variables.

Results

On average, the experimental group climbed 121 floors/week when prompted. There were significant reductions in fasting blood glucose, TC and LDL, as well as the derived measures of ‘bad’ cholesterol and the TC/HDL ratio in the experimental group. Post-experimental interviews indicated that the interruption to sitting was well tolerated.

Conclusion

Prompted stair climbing activity had impacts on health outcomes and was found acceptable to employees at work.

Trial registration

Ethics for this study was approved by Science, Technology, Engineering and Mathematics Ethical Review Committee, University of Birmingham with ethics reference number ERN_15_0491.

Supplementary information

The online version contains supplementary material available at 10.1186/s12889-022-14393-1.

Levels and patterns of physical activity and sedentary behavior in adults with and without visual impairment

BACKGROUND

Limited data are available on objectively measured physical activity (PA) and sedentary behavior (SB) among adults with and without visual impairment (VI).

OBJECTIVE

To compare PA and SB levels and patterns in adults with and without VI and to examine how these differ based on sex and day of the week.

METHODS

Thirty-two participants with VI and 32 participants without VI participated in this cross-sectional study. PA and SB were assessed using GT3X ActiGraph accelerometers during waking hours for 7 days, and variables were examined in terms of disability group, sex, and day of the week. Nonparametric Mann-Whitney U test and Wilcoxon signed-rank test were used, and significance was set at p < 0.05.

RESULTS

PA did not differ in terms of sex or day of the week in participants with VI. The PA of participants without VI was significantly higher for men than it was for women and was significantly higher during weekdays than on weekend days. Total sedentary time and the duration of SB breaks were significantly longer for female participants with VI than for those without VI. The number of sedentary bouts lasting ≥10 min during weekend days was significantly higher for participants with VI than for those without VI.

CONCLUSIONS

Most adults with and without VI did not meet the recommended levels of daily PA and spend a large portion of the day being sedentary. Interventions to enhance PA and reduce sedentary time in adults with and without VI are required.

Supporting Physical Activity for Informal Caregivers during and beyond COVID-19: Exploring the Feasibility, Usability and Acceptability of a Digital Health Smartphone Application, 'CareFit'

The COVID-19 pandemic has exposed how our global societies rely upon the care and support of informal (unpaid) caregivers: in the UK alone, there are an estimated 6.5 million informal carers. The caring role is not just precarious, it is often associated with high levels of stress, poor/deteriorating health and crisis points (hospitalisations, worsening of health). Fittingly, there has been much research in recent years focusing on mental health supports. A lesser explored area is physical health and physical activity. To address this, we conducted a real-world feasibility, usability and acceptability study of a novel codesigned digital health app for caregivers to improve levels of physical activity. Our study was designed to test the prototype app use for three weeks, following participants across questionnaires/in app data/qualitative data. Our findings (from 27 caregivers) highlights key knowledge gaps around physical activity-national guidelines were not reaching populations studies and behavioural change techniques hold promise to help support caregivers in the longer term. Our collective results support the acceptability, usability and feasibility of the Carefit app and warrant further investigation.

I Sit but I Don't Know Why: Investigating the Multiple Precursors of Leisure-Time Sedentary Behaviors

Background: Precursors driving leisure-time sedentary behaviors remain poorly investigated, despite their detrimental consequences. This study aimed to investigate the predictive validity of controlled and automatic motivational precursors toward reducing sedentary behaviors and being physically active on leisure-time sedentary behaviors. The influence of demographic, physical, socio-professional, interpersonal, and environmental variables was also examined and compared with the associations of motivational precursors. Methods: 125 adults completed questionnaires measuring controlled motivational precursors (i.e., intentions, perceived competence), demographical (i.e., sex and age), physical (i.e., body mass index), and interpersonal (i.e., number of children) variables. Regarding automatic motivational precursors, habit strength and approach-avoidance tendencies were captured using the Self-Report Behavioral Automaticity Index and a manikin task. Time at work was computed as a socio-professional variable, days of the week and weather conditions were recorded as environmental precursors. Participants wore an accelerometer for 7 days and leisure time was identified using notebooks. Associations between the different precursors and the leisure-time sedentary behaviors were examined in linear mixed effect models. Results: Intention to be physically active and habit strength toward physical activity were negatively associated with leisure-time sedentary behaviors. Sex, body mass index, time at work, number of children, day of the week, and weather conditions were more strongly associated with leisure-time sedentary behaviors. Conclusion: Our findings show that, in comparison with other variables, the influence of motivational precursors on leisure-time sedentary behaviors is limited. This study supports the adoption of a broad-spectrum of precursors when predicting sedentary behaviors.

Dose-response association between sedentary time and incident of diabetes in Chinese middle-aged and older adults: The 4C study

AIMS

To investigate the dose-response relationship of total sedentary time with incident diabetes in Chinese middle-aged and older adults.

METHODS

The present study followed 100,525 participants aged ≥ 40 years old from the China Cardiometabolic Disease and Cancer Cohort (4C) Study, which was a prospective study conducted in 25 communities across mainland China. Associations between sedentary time and incident diabetes were assessed with Cox regression and restricted cubic splines.

RESULTS

During a median follow-up of 3.8 years, 7,529 participants developed diabetes. After adjustment for multiple variables, high levels of sedentary time (≥ 30 h/week) was associated with increased risk for developing diabetes (hazards ratio, 1.08; 95 % confidence intervals 1.02, 1.14) compared with low levels of sedentary time (<20 h/week). Restricted cubic spline analyses revealed an inverted U-shaped relation between sedentary time with diabetes. Subgroup analyses found that the observed association remained significant in subgroup of individuals with body mass index (BMI) ≥ 25 kg/cm² or diastolic blood pressure (DBP) ≥ 90 mm Hg. However, the significant association was diminished in participants with sufficient physical activity (PA) (P = 0.22).

CONCLUSIONS

The multicenter, population-based, prospective study suggested an inverted U-shaped relation between sedentary time with diabetes. PA alleviated the deleterious effects associated with sedentary time.

Data-Driven User-Type Clustering of a Physical Activity Promotion App: Usage Data Analysis Study

Background

Physical inactivity remains a leading risk factor for mortality worldwide. Owing to increasing sedentary behavior (activities in a reclining, seated, or lying position with low-energy expenditures), vehicle-based transport, and insufficient physical workload, the prevalence of physical activity decreases significantly with age. To promote sufficient levels of participation in physical activities, the research prototype Fit-mit-ILSE was developed with the goal of making adults aged ≥55 years physically fit and fit for the use of assistive technologies. The system combines active and assisted living technologies and smart services in the ILSE app.

Objective

The clustering of health and fitness app user types, especially in the context of active and assisted living projects, has been mainly defined by experts through 1D cluster thresholds based on app usage frequency. We aimed to investigate and present data-driven methods for clustering app user types and to identify usage patterns based on the ILSE app function Fit at home.

Methods

During the 2 phases of the field trials, ILSE app log data were collected from 165 participants. Using this data set, 2 data-driven approaches were applied for clustering to group app users who were similar to each other. First, the common approach of user-type clustering based on expert-defined thresholds was replaced by a data-driven derivation of the cluster thresholds using the Jenks natural breaks algorithm. Second, a multidimensional clustering approach using the Partitioning Around Medoids algorithm was explored to consider the detailed app usage pattern data.

Results

Applying the Jenks clustering algorithm to the mean usage per day and clustering the users into 4 groups showed that most of the users (63/165, 38.2%) used the Fit at home function between once a week and every second day. More men were in the low usage group than women. In addition, the younger users were more often identified as moderate or high users than the older users, who were mainly classified as low users; moreover, the regional differences between Vienna and Salzburg were identified. In addition, the multidimensional approach identified 4 different user groups that differed mainly in terms of time of use, gender, and region. Overall, the younger women living in Salzburg were the users with highest average app usage.

Conclusions

The application of different clustering approaches showed that data-driven calculations of user groups can complement expert-based definitions, provide objective thresholds for the analysis of app usage data, and identify groups that can be targeted individually based on their specific group characteristics.

Relationships between adiposity distribution and metabolic health in preconception women in South Africa

Objective

Adipose tissue is a central regulator of metabolic health and a contributor to systemic inflammation. Patterns of adiposity deposition are important to understand for optimizing health. This study aimed to asses relationships between adiposity deposition and metabolic and inflammatory biomarkers in South African women prior to conception.

Methods

Non-pregnant, healthy women (n = 298) were recruited for this cross-sectional study via home visits. Body composition was measured by Dual X-ray Absorptiometry. Inflammation markers C-reactive protein (CRP), alpha1-acid glycoprotein (AGP), hemoglobin A1c (HbA1c), and blood pressure were scored according to risk. A summative metabolic health risk score was created for women with obesity. Generalized regression models assessed relationships between adiposity deposition and outcomes with adjustment for potential confounders.

Results

Obesity was present in 22% of women (mean age = 20.93 years). Fat mass index was associated with inflammation and metabolic health risk (β = 0.58; p < 0.01). Visceral fat, trunk:limb ratio, android:gynoid ratio, body mass index, weight, and waist circumference were positively associated with CRP, AGP, and metabolic health risk (p < 0.01). Weight was associated with Hba1c (β < 0.01; p < 0.05). Participants with obesity and low metabolic health risk had lower fat mass index and visceral fat than participants with obesity and higher metabolic health risk.

Conclusions

Black South African women accumulated excess adipose tissue in abdominal regions. While fat mass and body mass were associated with inflammation and metabolic health risk, women with obesity and with lower fat mass index and lower visceral adipose tissue were metabolically protected. Identification of women at risk for metabolic disease preconception could help ensure future healthy pregnancies and prevent transference of risk to offspring.

The COVID-19 pandemic: The importance of physical activity among faculty members

The novel coronavirus (SARS-CoV-2) disease 2019 (COVID-19) pandemic has posed serious challenge to societies worldwide. To prevent person-to-person transmission of the coronavirus and avoid associated morbidity and mortality, several public health measures have been introduced by various health organizations and authorities, such as social distancing policies and quarantine. While necessary, these public health measures are likely to have implications for people's physical activity behaviors. This viewpoint is intended for faculty members and focus on the importance of physical activity for health. Suggestions on how to stay physically active during the COVID-19 pandemic are also provided.

Aerobic or Muscle-Strengthening Physical Activity: Which Is Better for Health?

ABSTRACT

The Physical Activity Guidelines recommend performing 150 min of moderate- to vigorous-intensity aerobic physical activity (MVPA) per week. These guidelines also recommend muscle-strengthening physical activity (MSPA) on ≥2 d·wk-1 for additional benefits including muscular fitness and bone health. The majority of the scientific evidence supporting the PA recommendations for health comes from studies of MVPA while the possible contributions of MSPA in these findings have been overlooked historically. Emerging evidence suggests that MSPA can independently protect against major cardiometabolic risk factors, chronic diseases, and mortality. Additional data from clinical trials indicate that many of the well-known health benefits of exercise, like improvements in cardiovascular disease risk factors, are more robust with combined MVPA and MSPA. This review will clarify the relative benefits of MSPA versus MVPA on health-related outcomes to determine the best type of PA for health.

Association of Sitting Time With Mortality and Cardiovascular Events in High-Income, Middle-Income, and Low-Income Countries

Importance

High amounts of sitting time are associated with increased risks of cardiovascular disease (CVD) and mortality in high-income countries, but it is unknown whether risks also increase in low- and middle-income countries.

Objective

To investigate the association of sitting time with mortality and major CVD in countries at different economic levels using data from the Prospective Urban Rural Epidemiology study.

Design, Setting, and Participants

This population-based cohort study included participants aged 35 to 70 years recruited from January 1, 2003, and followed up until August 31, 2021, in 21 high-income, middle-income, and low-income countries with a median follow-up of 11.1 years.

Exposures

Daily sitting time measured using the International Physical Activity Questionnaire.

Main Outcomes and Measures

The composite of all-cause mortality and major CVD (defined as cardiovascular death, myocardial infarction, stroke, or heart failure).

Results

Of 105 677 participants, 61 925 (58.6%) were women, and the mean (SD) age was 50.4 (9.6) years. During a median follow-up of 11.1 (IQR, 8.6-12.2) years, 6233 deaths and 5696 major cardiovascular events (2349 myocardial infarctions, 2966 strokes, 671 heart failure, and 1792 cardiovascular deaths) were documented. Compared with the reference group (<4 hours per day of sitting), higher sitting time (≥8 hours per day) was associated with an increased risk of the composite outcome (hazard ratio [HR], 1.19; 95% CI, 1.11-1.28; Pfor trend < .001), all-cause mortality (HR, 1.20; 95% CI, 1.10-1.31; Pfor trend < .001), and major CVD (HR, 1.21; 95% CI, 1.10-1.34; Pfor trend < .001). When stratified by country income levels, the association of sitting time with the composite outcome was stronger in low-income and lower-middle-income countries (≥8 hours per day: HR, 1.29; 95% CI, 1.16-1.44) compared with high-income and upper-middle-income countries (HR, 1.08; 95% CI, 0.98-1.19; P for interaction = .02). Compared with those who reported sitting time less than 4 hours per day and high physical activity level, participants who sat for 8 or more hours per day experienced a 17% to 50% higher associated risk of the composite outcome across physical activity levels; and the risk was attenuated along with increased physical activity levels.

Conclusions and Relevance

High amounts of sitting time were associated with increased risk of all-cause mortality and CVD in economically diverse settings, especially in low-income and lower-middle-income countries. Reducing sedentary time along with increasing physical activity might be an important strategy for easing the global burden of premature deaths and CVD.

Cross-Sectional Associations of Sedentary Behavior and Sitting with Serum Lipid Biomarkers in Midlife

INTRODUCTION

Physical inactivity, excessive total time spent in sedentary behavior (SB) and prolonged sedentary bouts have been proposed to be risk factors for chronic disease morbidity and mortality worldwide. However, which patterns and postures of SB have the most negative impacts on health outcomes is still unclear. This population-based study aimed to investigate the independent associations of the patterns of accelerometer-based overall SB and sitting with serum lipid biomarkers at different moderate- to vigorous-intensity physical activity (MVPA) levels.

METHODS

Physical activity and SB were measured in a birth cohort sample ( N = 3272) at 46 yr using a triaxial hip-worn accelerometer in free-living conditions for 14 d. Raw acceleration data were classified into SB and PA using a machine learning-based model, and the bouts of overall SB and sitting were identified from the classified data. The participants also answered health-related questionnaires and participated in clinical examinations. Associations of overall SB (lying and sitting) and sitting patterns with serum lipid biomarkers were investigated using linear regression.

RESULTS

The overall SB patterns were more consistently associated with serum lipid biomarkers than the sitting patterns after adjustments. Among the participants with the least and the most MVPA, high total time spent in SB and SB bouts of 15-29.99 and ≥30 min were associated with impaired lipid metabolism. Among those with moderate amount of MVPA, higher time spent in SB and SB bouts of 15-29.99 min was unfavorably associated with serum lipid biomarkers.

CONCLUSIONS

The associations between SB patterns and serum lipid biomarkers were dependent on MVPA level, which should be considered when planning evidence-based interventions to decrease SB in midlife.